engine oil temp sensor

[dlaing]

Here are the voltages¹⁾ and, more importantly, what the ECU reads²⁾. The ADC column is what the AD converter should end up with. It's an integer between 0 (0 volts) and 1023 (5 volts).

 °C	 ohms	  mV	ADC
-40   100950	4927   1009
-30	53100	4863	996
-20	29120	4755	974
-10	16600	4586	939
 0	 9750	4333	887
10	 5970	3996	818
20	 3750	3571	731
25	 3000	3333	683
30	 2420	3087	632
40	 1600	2581	529
50	 1080	2093	429
60	  750	1667	341
70	  525	1296	265
80	  380	1011	207
90	  275	 775	159
100	  205	 601	123
110	  155	 468	 96
125	  100	 313	 64

 

^{1, 2)} this is based on the assumptions the ECU use a 1K5 fixed bridge resistor and a 10 bit ADC, like MyECU. I do not know for sure if that is the case.

Sorry, I think I misunderstood your footnotes.

The mV is without the bridge resistor and the ADC voltage is with the resistor, right?

So for me the mV is more important than the bridged ADC voltage.

From the mV on that chart you can simply measure the indicated temperature.

 

The most OBVIOUS benefit that someone like ratchet could get out of running a volt meter indicating engine temperature is that he could dial his variable resistor according to actual NUMBERS rather than seat of the pants subjectivity.

 

For owners of ECU tuning software, the map cells could be plotted to match reality without wild guess work about the actual temperature.

 

For people that just wand to add conductive goo, they could see a difference in numbers, before and after adding goo, and if the maximum mV/temperature was 468mV/110C before adding goo, and then off the charts at 300mV after adding goo, then they might want to rethink the goo strategy or add a heat sink, or a bigger heat sink.

 

But I am sure Ratchet still sees no value in knowing the indicated temperature..

 

Looking at the subtle changes in the chart below and knowing the huge difference in how the engine runs, with and without goo, I am guessing the goo changes the temperature reading by over 20C. (go on Ratchet, challenge that figure! with your seat of the pants and highly educated knowledge, but with no volt meter)

[raz]

Sorry, I think I misunderstood your footnotes.

The mV is without the bridge resistor and the ADC voltage is with the resistor, right?

So for me the mV is more important than the bridged ADC voltage.

From the mV on that chart you can simply measure the indicated temperature.

No, you really can't do without a bridge resistor! If you just apply 5V to the thermistor, where would you take the reading? At the 5V side? I can assure it will read 5V absolutely regardless of temperature. The ground side? Well, it will just show zero volts...

 

But if you put an 1,5 Kohm resistor in series with the resistor, you can measure the voltage where they connect, and that voltage will tell you

a) a voltage U (it's right there on your DVM)

a current I=(5-U)/1500

c) a resistance R=U/I

d) a temperature. To get that you need to apply a formula like Steinhart-Hart with some coefficients relevant for this thermistor. Or you do it the quick'n'dirty way (and also Good Enough®) with a table like the one MyECU uses.

 

The ADC column is just what decimal number the ADC will come up with that represents the voltage. For a 10 bit converter 0-5V, the formula is U/(5000/1024) where U is voltage in mV. It's just another representation of the mV column, with less resolution.

[dlaing]

Thanks Raz.

This may be more trouble than it is worth.

I figured it would be as easy as reading TPS voltage.

[Guzzi2Go]

...

From my multiple experiments over several weeks as presented previously, it was obvious that when thermo-compound is added to the holder, the temperature at the sensor tip, where the thermistor takes its reading, remains closer to the temp at the head over a greater period of time than it does with an air gap. In BOTH scenarios, however, it was equally obvious that there is a significant LAG TIME in the response of the sensor read to actual temp changes at the head, as determined by the relatively large MASS and THERMAL INERTIA of the sensor body, as discussed previously.

...

So, how does actually adding more MASS (heatsink) reduce THERMAL INERTIA and with it LAG TIME?

 

I am still missing a dimensioning input for a heatsink. What does seat of your pants tell you? Small one? Big one? Or maybe n-one?

 

ANALytical mind.... (you know)...

[Guest ratchethack]

So, how does actually adding more MASS (heatsink) reduce THERMAL INERTIA and with it LAG TIME?

 

I am still missing a dimensioning input for a heatsink. What does seat of your pants tell you? Small one? Big one? Or maybe n-one?

 

ANALytical mind.... (you know)...

For "working knowledge" and a grasp of the concepts involved, it helps a great deal to understand basic principles of heat flow and thermodynamics, as mentioned many times previously. Laboratory experience studying principles of thermodynamics is a big plus. Yes, I have, but you won't be acquiring the equivalent of a passing grade (or any kind of a grade) in undergrad Physics here, nor much of anywhere else on any Web Forum.

 

Adding mass to the sensor body would compound the thermal inertia problem IF that mass contributed to the capacity of the "dead end" heat reservoir by simply providing greater heat storage with no avenue for heat to escape. The heat sink doesn't do that. While it adds mass, that mass provides an "open door" escape route for the heat content of the sensor body, having the effect of decreasing the heat capacity of the sensor body continuously, at any engine temp above ambient, as I have described, as analyzed, tested and verified by actual road trial under multiple sensor/holder configurations (and thoroughly documented in post #280, p. 19) of this thread.

[Guzzi2Go]

For "working knowledge" and a grasp of the concepts involved, it helps a great deal to understand basic principles of heat flow and thermodynamics, as mentioned many times previously. Laboratory experience studying principles of thermodynamics is a big plus. Yes, I have, but you won't be acquiring the equivalent of a passing grade (or any kind of a grade) in undergrad Physics here, nor much of anywhere else on any Web Forum.

Actually, one would not find it anywhere, because basic principles of heat flow and thermodynamics speak quite the opposite. Nice try hiding behind pseudo scientific mumbo-jumbo, but there are a few that have, unlike yourself, actually read and comprehended these works and know when you are talking bullshit.

 

Or, alternatively, prove that you are right! Why don't you run a calculation (if you can), that will explain the purpose of heatsink. and how did you select THAT PARTICULAR ONE. I hope there are other reasons than its $2 price tag. Remember how did you select the 500k resistor? Was it because it was cheap? Is that the "scientific" approach?

 

Adding mass to the sensor body would compound the thermal inertia problem IF that mass contributed to the capacity of the "dead end" heat reservoir by simply providing greater heat storage capacity with no avenue for heat to escape. The heat sink doesn't do that. While it adds mass, that mass provides an "open door" escape route for the heat content of the sensor body, having the effect of decreasing the heat capacity of the sensor body continuously, at any engine temp above ambient, as I have described, as analyzed, tested and verified by actual road trial under multiple sensor/holder configurations (and thoroughly documented in post #280, p. 19) of this thread.

 

Ho, ho, ho! It seems that the post #280 changes on daily basis! I bet a case of that the heatsink will soon disappear from it, just as air gap did (seemed to be a good idea back then), and thermo-goo found its way in (which was a no-no earlier), toghether with a 1k pot (is it really important that it is linear?) where previously 500k one was (blamed it on the multimeter, didn't you?).

 

Pathetic! Is this what you call "science". It is just a proof that you have no cucking flue what you are doing.

 

As far as heatsink goes, you have cylinder head with all its mass and surface (fins) attached to the other end of the sensor. If heat is in need of "escaping" that is the "open door". There is no need to provide an "emergency exit". Quite the contrary.

[Greg Field]

Excellent! The response to this'll surely get us a few more pages toward the magic 40. By then, I'll have my patented square wheels ready for market, and Dunlop has promised a simultaneous introduction of matching tires. Get ready for a whole new standard of riding pleasure . . .

[emry]

I don't want to bum you out Greg, but maybe these gents already have the patent. Turns out my "Dial-a-Knob" was too close to other products and I was hit with a "infringement" lawsuit.

 

[Guzzi2Go]

Excellent! The response to this'll surely get us a few more pages toward the magic 40. By then, I'll have my patented square wheels ready for market, and Dunlop has promised a simultaneous introduction of matching tires. Get ready for a whole new standard of riding pleasure . . .

Hmmmm, dunno...

 

Ratchet has resorted to a nasty trick! Instead of adding new posts, he is changing existing ones.

 

I guess we all need to chip in....

[helicopterjim R.I.P.]

In case anyone forgot what this thread was about .......

 

Questions:

1 I was told ametal/brass replacement was available but the local guzzi distrubutor wasnt aware of one

2 Anyone explain to me how the hell you are supposed to screw the plastic stand off back into the head with decent tension and NOT breaking it?

3 Anyone else had a similar experience with poor running and this being teh solution?

[dlaing]

Questions:

1 I was told ametal/brass replacement was available but the local guzzi distrubutor wasnt aware of one

2 Anyone explain to me how the hell you are supposed to screw the plastic stand off back into the head with decent tension and NOT breaking it?

3 Anyone else had a similar experience with poor running and this being teh solution?

 

thanks !

 

nigev11

Answers(absolute subjective TRUTH):

1. Your dealer is a Vespa dealer.

2. According to Ratchet, don't be a Philistine, but according to others (like me) it is a crap shoot. It might snap in your fingers or it might take more than five foot pounds of torque. I suppose heating the engine and using liquid wrench might help you get it out. Putting it back in, I'd add anti-seize and finger tighten it. Make a regular habit of re-finger tightening it. If it continually loosens, replace anti-seize with mild Loctite and prepare to replace next time you need to pull it, which may be never...

Ratchet probably has some good advice for removing and installing.

3. Au contraire mon frere, my bike ran better with the plastic sensor adapter. Ratchet had similar experience. But Greg Field and others have run better with the brass.

[dlaing]

Anyone want to take a gander on what specs would be needed for a potentiometer that was would let the sensor signal through in a neutral position, and override up to maybe 30°C in both rich and lean directions?

Could we use a HD pf4c TPS? That would be dumb luck if it worked. If so, how would we wire it.

 

I suppose it be easier to just use switches and fixed resistors, but it might not be automatic enough.

One position bypassing sensor with a 100? ohm sensor for touring fuel efficiency.

One position bypassing sensor with a 1000? ohm sensor for road racer or hot weather stop light mode.

One position direct from sensor.

 

Or a bypass to a variable resistor.

 

Or have a switch to switch between:

Sensor only

Sensor and parallel resistor or rheostat

Sensor and series resistor or rheostat

 

Put it in a $50 kit and put Power Commander out of business!

[helicopterjim R.I.P.]

3. Au contraire mon frere, my bike ran better with the plastic sensor adapter. Ratchet had similar experience. But Greg Field and others have run better with the brass.

 

Anyone tried titanium? Surely someone has tried titanium!?

[Guest ratchethack]

SQUARE WHEEL UPDATE

 

 

My, my – How the pot gets stirred when something a little out o' the ordinary gets thrown into the mix. . . and now the expected raw, seething animosity seems to be a progressive thing! Why – I do b’lieve it’s become yet another Gift That Keeps On Giving!

 

Though in my OBLIGATORY GREAT WALLOPPING DISCLAIMER back in post #180 (p. 19), I clearly anticipated the usual leaping to false conclusions in group formation, and the usual pulling out of context without reading wot’s being responded to (and I haven’t been disappointed in the slightest on either score ), I’m nevertheless always amazed at the spittle-spattering conniption fits and defensive posturing, snarling, and teeth-baring that can be elicited hereabouts by something a little off the beaten path. . . especially when it’s backed by fairly well documented real-world experience, as opposed to the customary raw speculation based on wishful thinking, no experience a-tall, and, well, nothing. . .

 

As usual, those who seem to’ve got their dorks wrapped up in the tightest wads around the ol’ driveshaft here are those without ANY experience wotsoever with what they’re so worked up about. In this case, I refer, of course, to the use of a heat sink and added resistance with the OE sensor/holder. By my reckoning, the experience of the seemingly progressively threatened, deliriously enraged, and (most recently) spectacularly presumptuous and demanding with either one amounts to ZIP. . . Must be they somehow already know all there is to know about the operation of the OE sensor and holder with both heat sink and added resistance (despite not having shared any of it here), and therefore, they must figure they can’t possibly learn a single thing more, and anyone dumb enough to actually do something with either one and post about it here based on actual experience on the road -- Well, the reasoning behind this must go something like, "Why, since I don't understand it, it's just plain foolishness, clear and simple!"

 

This^ is truly a thing of awe and wonderment to behold. . . and yet, I find it’s as predictable as night following day. . . the only Q I ever have in advance on stuff like this is who the volunteers will be who step up to claim the roles . . . and I must confess a certain amount of surprise in one case to date on this thread. . .

 

Now this is just me, but not only have I learned quite a bit here about the operation of the head temp sensor/holder, per my objective as posted lo the many hundreds of posts ago when I resurrected this thread from a couple years back -- but I’m still learning -- and I reckon there's more to be learned yet. . .

 

After today’s outstanding back-country ride, I figured it’d be time do drop a follow-up mileage report.

 

For comparison, here’s the previous report:

 

Mileage with thermo-paste, heat sink, and variable resistor installed vs. mileage with OE sensor/plastic holder with .015" air gap, no thermo-paste, no heat sink, no var. resistor:

 

42.86 MPG today vs. ~40 MPG (typical) previously

(5.48 liters/100 km vs. 5.88 liters/100 km)

 

Ambient temps ~75-80°F (~24-27°C), a truly STELLAR, MANDATORY day for a favorite ride.

 

NOTE: "Library" PC III map dynoed with and for OE sensor/plastic holder in both cases, latest mileage on "hard flog" mountain climb, using entire tread edge-to-edge of Metz Z6's, 50-80 mph sweepers amply punctuated with 2nd gear hairpins and everything in between up to 7,260 ft. (2,213 m) from ~500 ft. elevation, all 166.4 miles back road, no slab. BTW: remains of last snow on the ground at the top.

 

NOTE (Part II): Previous attempts to run with above map and OE sensor/plastic holder WITH thermo-paste but WITHOUT heat sink and var. resistor unrideable at full operating temp, at idle, off-idle, trailing throttle, and low RPMs: Over-lean symptoms of missing, balking, coughing, surging, hunting, and snuffing. ALL PRIOR SYMPTOMS ABSENT WITH thermo-paste, heat sink, and variable resistor installed. Today, smooth as a billiard table at all RPMs, all throttle openings, and at all operating temps -- even at the summit after a long, hard haul up the legendary East Grade of Mount Palomar.

 

NOTE (Part III): I understand how bass ackwards, wrongedy-wrong and absurd this is (at least for some). . .

 

And yet, there you have it. . .

Today I didn’t get anywhere near the mileage I’d hoped for, even though the miles were mostly in similar terrain as above, less the mountain climb, and only up to ~4,400 ft (1,342 m). It was just after a rain and lots cooler, ~55 - 60°F (~12 - 15°C) and much slower going (typically 40 – 50 mph) and lots of on-off-on throttle behind numerous long lines of traffic winding up and down the foothills and canyons. Seems everyone came out after the rain, same as me.

 

Mileage: 36.55 MPG. But equally flawless running under all conditions and at all times.

 

And there you have it (Part II).

[Greg Field]

See the size of the contact patch available when you run square wheels? Dunlop assures me we'll be able to run cornering forces of 3g, or possibly more. Valentino Rossi's heard the hype and is about to sign on . . . catch the wave, boys . . .